A ripping late goal to Awer Mabil helped Adelaide United book a semi-final berth and score an exciting 2-1 elimination final triumph over Brisbane Roar at Adelaide Oval on Friday night.

Both sides had their chances in a high-quality, open contest, the Reds creating more but Brisbane looking good swarming forward.

The match tightened into an arm wrestle after half-time and seemed destined for extra time before Mabil, who substituted into the game for an underdone Marcelo Carrusca in the 70th minute sent United into the second week of the finals and ended the gallant Roar's title defence.

WHAT THEY SAID

“We’ve been talking about it since the start of this year, when we went out last year it wasn’t a great feeling and the win tonight is a reward for the boys for the hard work we’ve put in this year so we’re going to keep going.” – Adelaide United’s Awer Mabil

“We’re disappointed obviously because it was a must-win game and when you lose it’s obviously massively disappointing. It’s unfortunate, these things happen, you can only keep your chin up and get on with it.” – Brisbane Roar’s Jamie Young

GOALS

1-0 Goodwin (7')

James Donachie's clumsy, unnecessary foul on James Jeggo allowed the Reds to strike early.

Stepping up for the free kick from 20 yards, Goodwin's finish was of the highest order, curling a peach into the top corner past despairing Young, who seemed a tad late and unsighted by the Brisbane wall. Brilliant from Goodwin.

1-1 Broich (27')

A horror McGowan attempted back pass was intercepted by the ever-dangerous Broich.

The German marksman was never going to miss the one-on-one and, with plenty of space, he moved in for the kill and whipped it clinically past Eugene Galekovic.

2-1 Mabil (87')

Miguel Palanca shimmied past the Roar defence and cut a sweet cross to Mabil around the penalty spot.

The exciting young striker cracked it from close range where Young, falling to ground, got a desperate mitt on the pill but couldn't stop it finding the back of the net.

KEY MOMENT

With Brisbane gaining a firm grip in a pulsating second half, Corey Brown did well to find Solorzano in the penalty area in the 78th minute.

But the Roar substitute, from point-blank range, stumbled with his first touch and with only Galekovic to beat, tamely bunted the ball away innocuously from close range, denying Brisbane a golden chance to go up 2-1.

OPTA DATA KEY STATS

The Reds finally cracked that egg that has eluded them for so long.

Remarkably this was United's first win against Brisbane on South Australian soil since 2010, snapping and eight-match winless drought.

HIGHLIGHTS REEL

In the 80th minute, Sergio Cirio cut past Donachie with dazzle and drove the ball into the top corner.

His strike was on target and would have been the clincher but was denied by an absolutely world-class save from Young, who pulled off three stunning stops in the second half.

Mabil managed to find a way past Young later on.

BACK TO THE DRAWING BOARD

The hero Goodwin came agonisingly close to notching a brace and killing the contest in the 14th minute when his sliding tap-in spooned over the crossbar from five yards out after Cirio danced down the right and fed a sweet low cross.

Then in the 25th, Carrusca missed by a coat of varnish after dancing around Borello.

It didn't hurt the hosts in the long run - it just ensured they had to work extra hard for the win.

THE FINAL WORD

The Reds did it the hard way, fighting their way into the semis where they will take on Sydney FC away next weekend, with the winner advancing to the decider.

Brisbane's title defence never hit any real strides and they were given a lifeline by Perth Glory's expulsion for salary cap breaches. They were brave but not quite good enough.